Combined dyeing and creping process for organic derivative of cellulose fabrics



Patented Feb. 8, 1949 COMBINED DYEING AND CREPING PROCESS FOR ORGANIC DERIVATIVE F CELLU- LOSE FABRICS Cyril M. Croft and Walter H. Kindle. Cumberland, Md, aaalgnors to Celanese Corporation of America, a corporation of Delaware No Drawing. Application August 2, 1945, Serial No. 608.810

9 Claims. 1

This invention relates to the treatment of textile materials and relates more particularly to the production of fabrics, and particularly dyed fabrics, exhibiting crepe effects and made of or containing highly twisted crepe yarns having a basis of cellulose acetate or other organic derivative of cellulose.

An object of this invention is the provision of an improved process for the production of crepe fabrics made of or containing highly twisted crepe yarns of cellulose acetate or other organic derivative of cellulose.

Another objects of this invention is the production of cellulose acetate or other organic derivative of cellulose crepe fabrics dyed in shades extremely fast to light, washing, acid-fading and like agencies which normally have a. deleterious effect on such colored materials.

A further object of this invention is the production of colored cellulose acetate or other organic derivative of cellulose crepe fabrics dyed in deep, uniform and level shades by dyeing operations involving the use of vat and acid dyestuffs whereby said fabrics may be dyed rapidly in fast shades and the crepe effect developed in a relatively short time without the use of various crepe-promoting agents.

Other objects of this invention will appear from the following detailed description.

Fabrics of cellulose derivative materiab exhibiting crepe eifects are usually produced by incorporating in the fabrics cellulose acetate or other organic derivative of cellulose yarns to which a relatively high degree of twist has been imparted while said yarns are subjected to tlm action of hot aqueous media such as steam or hot water and giving these fabrics a treatment in hot, scouring or boil-off baths. The highly twisted yarn apparently undergo a buckling in the hot bath and impart the desired crepe effect to the fabrics. To aid in promoting the development of the desired crepe eflect, various crepepromoting agents are normally incorporated in the scouring or boil-oil bath in amounts of from 2 to 5% by weight. Suitable development of a commercially satisfactory degree of crepe normally requires a prolonged treatment in the securing or boil-on bath and such treatment may be anywhere from 1 to 2 or even 3 hours or more.

In the production of dyed crepe fabrics by dyeing fabrics wherein the crepe has already been developed, the depth of shade which may be produced is not entirely satisfactory and the resistance of such dyed creped fabrics to the deleterious effect of light, acid-fading and washing is an tial quantities of agents, such as sodium mmcyanate, ammonium thiocyanate, acetic acid or ethyl acetate, which have a swelling or softening action on the cellulose acetate or other organic derivative of cellulose materials. However, even with the addition of such swelling agents to the dyebaths, the latter are only effective in producing rather light shades. Furthermore, the use of such swelling or softening agents imparts a very harsh and undesirable hand to the dyed creped fabrics. A maximum effect is soon attained and greater depths of shade cannot be produced employing said dyeing media regardless of how much swelling agent is incorporated in the dyebath.

We have now found that the rate of creping of fabrics containing highly twisted crepe yarns of cellulose acetate or other organic derivative of cellulose may be substantially increased if said fabrics are padded with an aqueous organic liquid medium comprising at least by weight of a lower aliphatic alcohol prior to subjecting the fabric to the hot scouring or boil-ofl' bath in which a crepe effect is developed. By subjecting fabrics containing crepe twisted yarns to this pretreatment, the desired crepe effect is produced in said fabric in the boil-oil or scouring bath in an exceedingly short time. Thus, not only may the crepe development be eifectedgin a continuous manner, but the use of crepe promoting agents in the scouring or boil-oil bath may be eliminated as well.

Furthermore, we have also found that our novel process may be employed in connection with the production of crepe fabrics dyed in deep, level, uniform shades exhibiting unusual resistance to light, acid fading and washing. These improved dyed crepe fabrics may be obtained if the fabrics containing said highly twisted cellulose acetate or other organic derivative of cellulose crepe yarns are dyed by the mechanical impregnation methods above set forth and then developing the crepe in a hot scouring or boil-oil bath, as described. Advantagemisly. the dyed fabric is washed lightly before entering said boll-off bath. By dyeing the fabrics prior to developing the crepe, not only is a more satisfactory dyeing of the fabric obtained but, on entering the dyed fabric in the creping bath, the crepe effect is produced with great rapidity. In fact, the crepe development is so rapid in the case of fabric dyed prior to creping that the dyeing as well as the creping may be eflected in a substantially continuous manner.

The lower aliphatic alcohols which are suitable for effecting a pretreatment of the fabrics or for forming the solvent dyebath for simultaneous pretreatment and dyeing may be those alcohols which exert at least a swelling or softening action on the organic derivative of cellulose materials and which are solvents for the dyestufis employed. While we preferably employ ethyl alcohol, other lower aliphatic alcohols, such as, for example. methyl alcohol, propyl alcohol, isopropyl alcohol, isobutyl alcohol, butyl alcohol,

amyl alcohol, or mixtures of these alcohols may be used. The amount of alcohol present in the pretreatment or dyebath may vary, but it should, as stated, comprise at least 70% by weight of said bath. When employing ethyl alcohol in forming a solvent pretreatment or dyebath, the latter preferably contains from about '75 to 80% by weight of the alcohol.

Any suitable dyestuff having an affinity for cellulose acetate or other organic derivative of cellulose materials from a solvent dyebath may be employed, where the pretreatment is combined with simultaneous dyeing. Thus, the dyestuffs may comprise acid dyestuffs, or solubilized vat dyestufis of the Indigosol or Algosol type.

The concentration of the dyestuif in the dye liquor may vary, depending upon the particular shade desired on the material being dyed, and may be as low as 0.01% and up to 4.0% or more, based on the weight of the material to be dyed. After the solvent dyebath has been applied to the fabric containing the crepe twisted yarns by padding or spraying or other convenient method of mechanical impregnation. the dyed fabric is then preferably washed lightly before creping is effected. Where mechanical impregnation methods are employed, the period of immersion for the fabric in the solvent dyebath is relatively short and may be from about 1 /2 to about seconds, the fabric being passed to the pad at speeds which may range up to 45 yards per minute.

To develop the desired crepe effect in the pretreated fabric containing the highly twisted crepe yarns in either a dyed or undyed form after application of the solvent pretreatment bath, the fabric is subjected to treatment in a suitable aqueous creping or boil-oi! bath. The aqueous boil-o3 bath preferably comprises an aqueous solution of a suitable detergent or wetting agent, such as, for example, a 0.5% aqueous solution of sulfated lauryl alcohol. The rate of crepe development, in the case of fabrics treated in accordance with our novel process, is so rapid that the use of other crepe-promoting agents is quite unnecessary and may be entirely eliminated.

The temperature at which the boil-oil or creping bath is maintained may vary from about 90 to 99 C., and the desired crepe effect in the treated fabric may be produced by maintaining said fabric in the hot scouring or boil-off bath for a period of from about 3 to minutes. The normal creping period even with the aid of crepepromoting agents is, as stated. from 1 to 3 hours or more.

In order further to illustrate our invention. but

4 without being limited thereto, the following examples are given:

Example I A fabric having a warp of '72 ends per inch of cellulose acetate yarns of 150 denier having 3 turns per inch and a weft of 76 picks per inch of cellulose acetate yarns of 2 ply, 120 denier having '77 turns per inch therein, which twist has been inserted in the presence of steam, is lightly washed on a jig to remove any oils or sizing, dried under tension and then padded with an aqueous solution containing 75% by weight of ethyl alcohol. The fabric is washed lightly after the application of the alcohol solution and then. entered into a boil-oil bath comprising a, 0.5% aqueous solution of sulfated lauryl alcohol maintained at a temperature of 98 C. The fabric is passed through the boil-off bath at such a speed that it is subjected to the action of the bath for 5 minutes. A very satisfactory degree of creping develops in this short period of time.

Example I! per inch and a weft of 80 picks per inch of cellulose acetate yarn of denier having '77 turns per inch, which twist has been inserted in the presence of steam, is lightly washed on a. jig to remove any oils or sizing and, after drying, is pad dyed with a dyebath having the following composition:

Parts by weight The dye liquor is maintained at a temperature of 2'1 to 30 C. during dyeing and the fabric is passed continuously through the dyebath at the rate of 20 yards per minute, the path being sufficiently extended so that the fabric is immersed in the liquor for 10 seconds. The fabric laden with the dye liquor is then passed over an expander bar and through the nip of a padding mangle, the rolls being spaced so that the fabric retains 60% of its own weight of the dye liquor. After leaving the pad the fabric, now dyed in a lime shade, is washed lightly in water.

The fabric is then passed directlyin a continuous manner to a boil-off bath comprising a 0.5% aqueous solution of Gardinol," e. g. sulfated lauryl alcohol, maintained at a temperature of 98 C. The speed of the fabric passing through the bath is adjusted so that each portion of the fabric is subjected to the action of the hot crepin bath for 10 minutes. during which period a very satisfactory degree of crepe develops. The dyed creped fabric is then frame dried. If desired, the fabric may be over printed in any desired pattern with a suitable printing composition containing a vat dyestufi and the latter may then be developed in the manner well known to the art. The dyed fabric obtained exhibits materially improved resistance to light, acid-fading and washing as compared to a dyed crepe fabric of the same construction which has been creped before being dyed.

Thus. a. portion of the dyed fabric may be exposed in the Fadeomete'r" for 30 hours at 105 C. with substantially no change in shade. when creped fabric. dyed after being creped, is subjected to the same condition of exposure in the "Fadeometer the shade not only fades considerably but becomes noticeably duller. When fabrics dyed and creped in accordance with our novel process are subjected to the standard A. A. '1. C. C. wash test. no change in shade is produced. Fabric creped first and then dyed suflers a washdown in shade.

Example III A fabric of the same construction as that described in Example I is pad dyed in a bath having the following composition:

The dye liquor is maintained at a temperature of 27 to 30 C. during dyeing and the fabric is padded continuously through the dyebath at a rate of 25 yards per minute, the path being of sufficient length so that the fabric is immersed in the liquor for 8 seconds. The fabric is then passed through the nip of a padding mangle and allowed to retain 60% of its own weight of the dye liquor. The fabric. dyed a royal blue shade, is washed lightly in water and then entered into a bath comprising a 0.5% aqueous solution of sulfated lauryl alcohol at 98 C. The desired degree of crepe is developed in 5 minutes. The dyed fabric exhibits increased resistance to acid fading as compared to like fabrics dyed after crepingl Example IV A fabric having the same construction as that given in Example II is dyed in a dyebath of the following composition:

passed through the dyebath which is at a temperature of 27 to 30 C. at the rate of yards per minute, the fabric being immersed therein for 10 seconds. I

The leuco dyestuif is developed by oxidizing the padded fabric for 20 minutes at 40 C. in a developing bath of the following composition:

The dyed fabric is then entered into a creping bath comprising a 0.5% aqueous solution of sulfated lauryl alcohol held at a temperature of 00" C. and the desired creped effect is produced in 5 minutes. The fabric, dyed a bright green shade, does not undergo any change in shade when exposed for 40 hours in the "Fadeometer" or on exposure for 40 hours in the standard A. A. T. C. C. acid-fading test. Furthermore, the fabric is dyed in a considerably heavier shade than is attainable when said fabric is dyed after being boiled-off. The washdown in the shade when the dyed fabric is secured following creping is also considerably less than that normally experienced with a fabric yed in the same manner but after the crepe has been developed.

Eaample V A fabric having the same construction as that given in Example I is pad dyed with a dyebath of the following composition:

Alizarine Cyanine Green Parts by weight GHN (C. I. 1078) 050 Ethyl alcohol 24,000 Water 10,000 Sodium thiocyanate 500 The dyebath is maintained at a temperature of 27 to 30 C. and the fabric is passed through the dyebath at a speed of 20 yards per minute whilebeing immersed therein for 10 seconds. The fabric is dyed a medium green shade and after being washed lightly is then creped in a 0.5% aqueous solution of sulfated lauryl alcohol at a temperature of 98 C., the crepe being developed in 5 minutes. The dyed fabric exhibits excellent light fastness, no change in shade being observed after 20 hours exposure in the Fadeometer. When the same fabric is dyed after the crepe is developed, the light fastness is found to be unsatisfactory.

It is to be understood that the foregoing detailed description is given merely by way of iilustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. Process for the production of colored fabrics exhibiting crepe effects, which comprises mechanically impregnating a fabric containing yarns of filaments of organic derivative of cellulose, which yarns have been crepe twisted while being subjected to the action of a hot aqueous fluid, with an aqueous alcoholic solution of a dyestuii', said aqueous alcoholic solution comprising at least 70% by weight of a lower aliphatic alcohol which is a solvent for the dyestufl, washing said fabric and then treating the dyed fabric with a. hot aqueous creping bath.

2. Process for the production of colored fabrics exhibiting crepe effects, which comprises mechanically impregnating a fabric containing yarns of filaments of cellulose acetate, which yarns have been crepe twisted while being subboiled to the action of a hot aqueous fluid. with an aqueous alcoholic solution of a. dvestuif, said aqueous alcoholic solution comprising at least 70% by weight of a lower aliphatic alcohol which is a solvent for the dyestuff, washing said fabric and then treating the dyed fabric with a hot aqueous creping bath.

3; Process for the production of colored fabrics exhibiting crepe effects, winch comprises padding a fabric containing yarns of filaments of cellulose acetate, which twisted while being subjected tothe action of a hot aqueous fluid, with an aqueous alcoholic solution of a dyestuif, said aqueous alcoholic solution comprising at least 70% by weight of ethyl alcohol, washing said fabric and then treating the dyed fabric with a hot aqueous creping bath.

4. Process for the production of colored fabrics exhibiting crepe effects, which comprises padding a fabric containing yarns of filaments of cellulose acetate, which yarns have been crepe twisted while being subjected to the action of steam with an aqueous alcoholic solution of a dyestufl, said aqueous alcoholic solution comprising at least 70% by weight of ethyl alcohol, washing said fabric and then treating the dyed fabric with a hot aqueous creplns bath.

yarns have been crepe 5. Process for the production of colored imbrics exhibiting crepe eifects, which comprises padding a fabric containing yarns oi filaments oi cellulose acetate, which yarns have been crepe twisted while being subjected to the action of a hot aqueous fluid, with an aqueous alcoholic solution of a dyestufl, said aqueous alcoholic solution comprising at least 70% by weight of a lower aliphatic alcohol which is a solvent for the dyestufl', washing said fabric and then treating the dyed fabric with a hot aqueous creping bath.

6. Process for the production of colored iabrics exhibiting crepe effects, which comprises padding a fabric containing yarns of filaments of cellulose acetate, which yarns have been crepe twisted while being subjected to the action of a hot aqueous fluid, with an aqueous alcoholic solution of a dyestuil', said aqueous alcoholic solution comprising at least 70% by weight of ethyl alcohol, washing said fabric and then treating the dyed fabric with a hot aqueous creping bath containing a wetting agent.

'7. Process for the production of colored rabrics exhibiting crepe efl'ects, which comprises padding a fabric containing yarns oi filaments of cellulose acetate, which yarns have been crepe twisted while being subjected to the action of a hot aqueous fluid, with an aqueous alcoholic solution of a dyestuii, said aqueous alcoholic solution comprising at least 70% by weight oi. ethyl alcohol, washing said fabric and then treating the dyed fabric with a hot aqueous creping bath at a temperature 01' 90 to 99 C.

8. Process for the production of colored iabrics exhibiting crepe eiIects, which comprises padding a fabric containing yarns of filaments of cellulose acetate, which yarns have been crepe twisted while being subjected to the action or a hot aqueous iluid, with an aqueous alcoholic solution of a dyestufl, said aqueous alcoholic solution comprising at least 70% by weight or ethyl alcohol, washing said fabric and then treating the dyed Iabric with a hot aqueous creping bath at a temperature oi 90 to 99 C. for from 3 to 15 minutes.

9. Process (or the production of colored tabrics exhibiting crepe eflects, which comprises padding a fabric containing yarns of filaments o! cellulose acetate, which yarns have been crepe twisted while being subjected to the action of steam, with an aqueous alcoholic/solution oi a dyestufl, said aqueous alcoholic solution comprising at-least 70% by weight of ethyl alcohol, washing said fabrics and then treating the dyed fabric with a hot aqueous creping bath at a temperature 0! 90 to 99 C. for from 3 to 15 minutes.

CYRIL M. CROFT. WALTER H. HINDLE.

REFERENCES CITED The iollowing references are of record in the tile of this patent:

UNITED STATES PATENTS Number Name Date 1,947,928 Becir Feb. 20, 1934 2,089,241 Whitehead Aug. 10, 1937 2,118,840 Dreyfus May 31, 1938 2,344,973 Croft Mar. 28, 1944 

